Film drying machine



Sept- 0 1941- M. NIERSBACH 2,257,394

FILM DRYING MACHINE Filed May 6, 1940 2 Sheets-Sheet 1 INVEN TOR.

ATTORNEY Sept. 30, 1941. M. NIERSBACH 2,257,394

FILM DRYING MACHINE I Filed May 6, 1940 2 Sheets-Sheet 2 Fia-L- a;IgVFNTOR. 95M.

ATTORNEY l-lof Patented Sept. 30, 1941 UNITED STATES PATENT OFFICEApplication May a, 1940, Serial No. 233,419

3 Claims. (01. 34-23:)

This invention relates to improvements in film drying machines, and moreparticularly to apparatus having a novel construction capable of rapidlydrying developed film or photographic plates without danger of damagingthe same. 7

'An object of my invention is to provide an improved mm drying machineembodying novel improved machine of the character described,

having novel thermostatic means for controlling the temperature ofthemoving air directed upon the mm which is being treated, whereby damagefrom excessive heat may be eliminated.

Other and further objects of my invention will be pointed outhereinafter, or will be indicated in the appended claims, or will beOViOlls to one skilled in the art upon an'understanding of the presentdisclosure. For the purpose of this application I have elected to showherein certain forms and details of a film drying machine representativeof my invention. It is to be understood, however, that the embodiment ofmy invention herein shown'and described is for the purpose ofillustration only, and that therefore it is not to be regarded asexhaustive of the variations of the-invention; nor is it to be given aninterpretation such as might have the effect of limiting the'claimsshort of the true and most comprehensive scope of the invention in theart. In the accompanying drawings: Fig. 1 is a perspective view of afilm drying machine embodying my invention.

Fig. 2 is a vertical sectional view of the same; mg. 3 is a sectionalview taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on the line Fi 2; and Fig. 5 is awiring diagram of the electrical circuit constituting a part of myinvention.

Referring to the drawings, the numeral I designates a suitably shapedand p portioned cabinet having a hinged lid '1, an air inlet opening 3in its front side, and air outlet openings 4 in its front and lateralwalls. The lidis preferably provided with a suitable handle I foropening and closing the same, and if desired,

'meansofthecustomarykindmaybeusedtoprevent the lid from being swung inan upward direction beyond a certain position. Mounted on a side of thecabinet I is an electrical switch I for enclosure.

opening and closing the circuit leading from a source of electricalenergy to a fan, a heating unit and a thermostat.

Extending rearwardly from the air inlet open ing 3 is an air duct ihaving its rear end connected to an upwardly disposed air duct 1 whichis provided at its. upper end with a discharge manifold 8. The manifoldl is suitably secured at its discharge end to the rear wall of an outerenclosure 9, preferably of rectangular cross sectional shape. Air fromthe manifold is discharged into the outer enclosure through an elongatedhorizontal slot or opening l0 provided in its rear walL-and an angulardeflector H supported on the rear wall of an inner enclosure I2 ispositioned within the said opening in such a manner that the airdischarged from the manifold is horizontally divided as it passes intothe outer enclosure, and is thereby directed upwardly and downwardly asindicated by the arrows in Fig. 2.

- The inner enclosure I2 is of approximately the same height as theouter enclosure 9 and their cross sectional shapes are preferably thesame, but the innerenclosure is somewhat smaller with respect to itslateral dimensions than the outer The inner and outer enclosures areconcentrically positioned with respect to each other, thereby providinga four-sided intervening air space or channel l3 between the walls ofthe two enclosures. The space It is closed at its upper and lower endsby rectangular members It secured to the upper and lower ends of theinner and outer enclosures. The walls of the inner enclosureareprovidedwith perforations I! of varying size forthe passage from theintervening space ll of air into the said inner enclosure. The upper andlower ends of the inner enclosure are open so as to permit the airentering the same to freely circulate throughout its interior andthereafter pass from the said open ends into the area of the cabinetlocated outside the outer enclosure, from whence it escapes through thedischarge openings 4. The perforations I! in the walls of the innerenclosure II are graduated in size seat to cause air under pressure toenter at all four sides. The smallest of the perforations are located inthe rearwall; the largest of the perforations are located in the frontwall; and the medium size perforations are located in the interveningside walls. Thus by having the perforations of the various wallsincrease in size from the rear to the front in proportion to thedecrease in the pressure of the air as the front area of the space ll isapproached, the air pressure of the air entering the enclosure l2 at itsfour sides is substantially uniform.

A suitable supporting structure It is provided a in the cabinet formaintaining the various parts of the device in their respectivepositions. The outer enclosure 9 is mounted on the supporting structurei6 and the walls of the cabinet I as by angle irons l1, and the innerenclosure i2 is held in place by the rectangular members H which aresecured to the opposite ends of the said enclosures.

Mounted in the air duct 6 in front of an. electricfii heating unit I8.is an electric fan l9 which is capable of drawing air into the said ductthrough the inlet opening 3 and propelling it past the heating unit withsufficient pressure to insure its reaching the interior of the innerenclosure H with an appreciable unspent force. A motor 20 for actuatingthe fan, the heating unit l8, and a thermostatically controlled switchat are electricallyconnected in the electric circuit which is controlledby the switch 5. When the circuit is closed by the switch 5, the motor20 is energized and the fan causes a circulation of air through theducts 6 and I, through the intervening space l3, through theperforations l in the walls of the inner enclosure l2, through and outthe open ends of the latter, and thence through the outlet openings 4 inthe cabinet. The therthrough the inner enclosure may be automaticallycontrolled. The air, when subjected to heat generated by the heatingunit ll, becomes sufficiently dry to readily absorb moisture. The dryand warm air, upon contacting the moist film,

plates or sheets 22 suspended in the inner enclosure [2 by means ofcross rods 23 and frames 24, readily dries the same. The cross rods '23are preferably supported in spaced relationship by grooved members 25positioned adjacent the open upper end of the inner enclosure It. Ifpreferred, the film, sheets or other material to be treated, may besuspended in the inner enclosure by any suitable means other than thatherein described. Y

Having described my invention, what I claim is:

1. In apparatus of the kind described, an inner enclosure of rectangularcross sectional shape having a plurality of air inlet holes in each ofits sides, and its top end open for the passage of air from itsinterior, the said inner enclosure having its walls positionedvertically, an outer enclosure of rectangular cross sectional shapehaving air inlet means in oneof its sides, thesaid outer enclosure beingpositioned around the inner enclosure with its side walls in spacedrelation to the side walls of the inner. enclosure so as to provide anair channel encircling the inner enclosure, the said air channel beingclosed at its top and bottom, means for supporting material to betreated in the inner enclosure, an enclosing cabinet within which theenclosures are housed, air inlet and air outlet means in the walls ofthe cabinet, closure means normally closing the upper end of thecabinet, an air duct leading from the air inlet of the cabinet to theair inlet means of the outer enclosure, a. fan for discharging air underpressure through the air duct to the air channel, whereby air underpressure may be forced into the inner enclosure for the treatment of thematerial supported therein, an electric heater in the air duct forheating the air discharged therethrough, and a thermostatic controlmeans positioned in the air circulating system and electricallyconnected in the circuit of the electric heater, whereby the flow ofelectrical energy to the heater may be automatically controlled inaccordance with the temperature changes of the air circulated throughthe inner enclosure.

2. In apparatus of the kind described, an inner enclosure having atleast one of its opposite ends I open and its walls perforated to admitair to its interior, means for supporting material tobe treated insidethe inner enclosure, an outer enclosure disposed laterally around theinner enclosure and spaced therefrom toprovide an air channel encirclingthe inner enclosure, the said air channel being closed at its oppositeends, an enclosing cabinet in which the enclosures are housed havingair. inlet and air outlet means, closure means in the cabinet locatedadjacent an open end of the inner enclosure, an air duct connecting theair inlet means of the cabinet with the air channel, air heating meansin the air duct, and means in the air duct for forcing. air underpressure into the air channel, whereby said air may be circulatedthrough the interior ofthe inner enclosure to treat the materialsupported therein.

3. In apparatus of the kind described, an inner enclosure having its topend open and its walls perforated to admit air to its interior, means atthe top of the inner enclosure forsupporting material to be treatedinside the enclosure, an outer enclosure disposed laterally around theinner enclosure and spaced therefrom to provide an air channelencircling the inner enclosure, the said air channel being closed at itsupper and lower ends, an air enclosing cabinet in which the enclosuresare housed having air inlet and air outlet means, and an opening in itsupper side, a closure for the opening in the cabinet, an air ductconnecting the air inlet meansof the cabinet with the air channel,electrically operated means in the air duct for forcing air underpressurethrough the duct and into the air channel,

whereby said air may be circulated through the i an electrical circuit,and an electrical thermostatic control means positioned in the aircirinterior of the inner enclosure to treat the material supportedtherein, an electrical heating element positioned in the air duct andconnected in culating system near the inner enclosure and con-.

